xref: /freebsd/lib/libc/rpc/rtime.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2009, Sun Microsystems, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are met:
9  * - Redistributions of source code must retain the above copyright notice,
10  *   this list of conditions and the following disclaimer.
11  * - Redistributions in binary form must reproduce the above copyright notice,
12  *   this list of conditions and the following disclaimer in the documentation
13  *   and/or other materials provided with the distribution.
14  * - Neither the name of Sun Microsystems, Inc. nor the names of its
15  *   contributors may be used to endorse or promote products derived
16  *   from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  * Copyright (c) 1988 by Sun Microsystems, Inc.
33 
34  */
35 
36 /*
37  * rtime - get time from remote machine
38  *
39  * gets time, obtaining value from host
40  * on the udp/time socket.  Since timeserver returns
41  * with time of day in seconds since Jan 1, 1900,  must
42  * subtract seconds before Jan 1, 1970 to get
43  * what unix uses.
44  */
45 #include "namespace.h"
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include <errno.h>
50 #include <sys/types.h>
51 #include <sys/socket.h>
52 #include <sys/time.h>
53 #include <netinet/in.h>
54 #include <stdio.h>
55 #include <netdb.h>
56 #include "un-namespace.h"
57 
58 extern int _rpc_dtablesize( void );
59 
60 #define	NYEARS	(unsigned long)(1970 - 1900)
61 #define	TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
62 
63 static void do_close( int );
64 
65 int
66 rtime(struct sockaddr_in *addrp, struct timeval *timep,
67     struct timeval *timeout)
68 {
69 	int s;
70 	fd_set readfds;
71 	int res;
72 	unsigned long thetime;
73 	struct sockaddr_in from;
74 	socklen_t fromlen;
75 	int type;
76 	struct servent *serv;
77 
78 	if (timeout == NULL) {
79 		type = SOCK_STREAM;
80 	} else {
81 		type = SOCK_DGRAM;
82 	}
83 	s = _socket(AF_INET, type, 0);
84 	if (s < 0) {
85 		return(-1);
86 	}
87 	addrp->sin_family = AF_INET;
88 
89 	/* TCP and UDP port are the same in this case */
90 	if ((serv = getservbyname("time", "tcp")) == NULL) {
91 		return(-1);
92 	}
93 
94 	addrp->sin_port = serv->s_port;
95 
96 	if (type == SOCK_DGRAM) {
97 		res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
98 			     (struct sockaddr *)addrp, sizeof(*addrp));
99 		if (res < 0) {
100 			do_close(s);
101 			return(-1);
102 		}
103 		do {
104 			FD_ZERO(&readfds);
105 			FD_SET(s, &readfds);
106 			res = _select(_rpc_dtablesize(), &readfds,
107 				     (fd_set *)NULL, (fd_set *)NULL, timeout);
108 		} while (res < 0 && errno == EINTR);
109 		if (res <= 0) {
110 			if (res == 0) {
111 				errno = ETIMEDOUT;
112 			}
113 			do_close(s);
114 			return(-1);
115 		}
116 		fromlen = sizeof(from);
117 		res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
118 			       (struct sockaddr *)&from, &fromlen);
119 		do_close(s);
120 		if (res < 0) {
121 			return(-1);
122 		}
123 	} else {
124 		if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
125 			do_close(s);
126 			return(-1);
127 		}
128 		res = _read(s, (char *)&thetime, sizeof(thetime));
129 		do_close(s);
130 		if (res < 0) {
131 			return(-1);
132 		}
133 	}
134 	if (res != sizeof(thetime)) {
135 		errno = EIO;
136 		return(-1);
137 	}
138 	thetime = ntohl(thetime);
139 	timep->tv_sec = thetime - TOFFSET;
140 	timep->tv_usec = 0;
141 	return(0);
142 }
143 
144 static void
145 do_close(int s)
146 {
147 	int save;
148 
149 	save = errno;
150 	(void)_close(s);
151 	errno = save;
152 }
153